title: GMR sensors: magnetoresistive behaviour optimization for biological detection by means of superparamagnetic nanoparticles.
abstract: An immunomagnetic method for the selective and quantitative detection of biological species by means of a magnetoresistive biosensor and superparamagnetic particles has been optimized. In order to achieve this, a giant magnetoresistive [Co (5.10nm)/Cu (2.47 nm)](20) multilayer structure has been chosen as the sensitive material, showing a magnetoresistance of 3.60% at 215 Oe and a sensitivity up to 0.19 Ω/Oe between 145 Oe and 350 Oe. The outward gold surface of the sensor is biofunctionalized with a Self-Assembled Monolayer (SAM). In addition, three different types of magnetic labels have been tested. 2 μm diameter magnetic carriers (7.68 pg ferrite/particle) have shown the best response and they have induced a shift in the magnetoresistive hysteresis loops up to 9% at 175 Oe.
authors.affiliation: CEIT, Paseo de Manuel Lardizábal, N° 15, 20018 Donostia-San Sebastián, Spain. aiaiaitor@gmail.com
authors.forename: A
authors.initials: A
authors.lastname: Manteca
authors.forename: M
authors.initials: M
authors.lastname: Mujika
authors.forename: S
authors.initials: S
authors.lastname: Arana
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation*; D008280:Magnetics / Q000295:instrumentation*; D058185:Magnetite Nanoparticles / Q000737:chemistry*
chemical_list: D058185:Magnetite Nanoparticles